The present invention relates to a terminal block assembly of the type used for terminating telephone and data transmission lines on distribution frames, and is constructed to control the dielectric constant between selected pairs of terminals for reduction of unwanted cross-talk. Symmetrical insulation displacement terminals are also disclosed.
A terminal block assembly of standard configuration is shown in U.S. Pat. No. 5,127,845. The terminal block has a body having a series of evenly-spaced holes that are arranged such that four holes are aligned in lateral rows. The holes are arranged in aligning columns of evenly spaced holes extending in direction of the longitudinal length of the terminal block. The outer edges of the terminal block have fanning strips, one aligned with each of the rows of openings, and terminal clips are inserted into the openings and held in place with a suitable retainer. The terminal clips project through the openings and are capable of receiving wires, such as communication wires. The terminal clips disclosed are not symmetrical and have to be oriented so that a pair of terminals on one side of the block has to be reversed 180.degree. from the pair of terminals in the same row on the opposite side of the block.
Another prior art device of the general type is shown in U.S. Pat. No. 5,324,211, wherein the same shape terminal clip is used in a terminal block that has columns of holes which are spaced at uneven intervals in order to reduce cross-talk between selected ones of the terminal clips. The hole separation is such that the space between tip-and-ring conductors of a pair of wires is reduced relative to the separation between the terminal clips holding wires from two different pairs of wires.
In both of the above-mentioned patents and in the other prior art, the terminal clips are formed in side by side pairs and are not symmetrical about a center line, so they have to be oriented appropriately for assembly into the terminal block. This increases manufacturing time and requires specialized fixtures.